It won't kill fungal spores, and probably not the fungus itself. But it will stop it growing!
A vacuum can potentially introduce other problems though. If too strong a vacuum is used it will cause lubricants from the aperture to migrate around the lens... Normal household vacuums (from vacuum cleaners etc.) are probably OK.

For some reason I couldn't get the full path to the larger images I'd uploaded elsewhere, only the web page that shows them.
I was a bit short for time so decided this was the best compromise - as I've also mixed up the links it seems I was wrong.

I'll have another go later when I've got time to do it properly!

Although its sometimes tempting don't leave your lenses in a car over night (Unless they're in a desiccated air tight container). Cars tend to produce a lot of condensation!

When regenerating desiccant packs bare in mind:

Some bags (such as the Radio spares ones) are constructed with a hot glue that comes unstuck below 100°C. Make sure you dry them on a tray or similar or you might end up with silica gel scattered in your oven! Fortunately the vacuum oven at work will dry them out nicely at 70°C.

A few desiccant packs use molecular sieves instead of silica gel. It absorbs more water but needs higher temperatures to dry out (over 200°C)

Last Saturday was 'World Pentax Day' and I was working. Fortunately there were several gaps in testing when I was able to get out with the camera

1 Smith rejoins after a spin:

Bigger version

2 Pit Lane during qualifying:

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3 Flashy Porsche:

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4 Scottish Classics 1:

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5 Scottish Classics 2:

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I'm not suprised the repair is uneconomic, labour alone would probably be getting on for the cost a replacement K100 from e-bay.

Whilst 4-years is a long time in digital tech (as cabstar points out) I think you've been unlucky to have it die so soon. There are certainly still people using the *istD. [Yes Gary people do still keep TVs etc that long. We've had our main TV more than 4 years & we got it second hand! Our second TV is over 15 years old]

How much use did it get?
On occation I've shot over 1000 pictures in one day, though my average will be much lower (under 100?)
With film I'd expect there are few enthusiasts that shoot as much as 1 film a week - Which works out at 1800 shoots a year for a trigger happy enthusiast (I never shot more than 500/year with film).
Your K100 may well have taken more pictures than Peter's Canon EOS 1n!

I've had similar problems with the QR on my camera. It gradually works loose (probably due to the hand strap mounting on uit) so the camera can wobble when I do use it on the tripod.
I've been considering adding a stip of double sided carpet tape between the QR & the camera. It would make it difficult to remove - but it live on there so that no great issue until I upgrade the camera.

Hi & welcome to the forum.
It's nice to have the question asked this way round

Most of the DA series lenses will not cover a full 35mm negative (giving variable amounts of vignetting) but a few apparently will be OK. The older FA, F, A, M or K series were all designed for film though also work with the DSLRs.

If your lenses are without aperture rings then they will be very limited on the earler film SLRs but anything after the ME super should (I think) be able to control the aperture from the camera body.

I've never used an autofocus film SLR which might be the best models to consider...
If your not bothered with AF & have aperture rings the MX & ME models are my favorites (I could never afford an LX) the ME super & P50 I've used were both nice cameras (giving aperture control) but somehow never had quite the same appeal to me.

In any event you should find a good range of models available very cheaply second hand, shame about the cost of film/processing...

The K100d was simple (a switch on the back) with the K7 it still takes a few seconds - IIRC you have to rotate the rear dial 3or4 clicks to get to the right page then go up one to get to the bottom entry & toggle that. (A couple of times I've toggled it with the side button then pressed OK only to see it change back.
Until a couple of weeks ago I never touched it, as SR is turned off anyway when the timer is used (with the tripod). It's a shame the camera does auto detect the in lens OS - then I wouldn't have to remember to switch it

I'll be heading up to Knockhill for the bank holiday weekend in August. But I'll be working during the Day so will only have early morning & the evening for photography away from the track. Are there any gems near Dumfermline that I should explore?

It's an 8+ hour drive to get there so I don't often go to Scotland except when working, I've managed to get one trip a year through work for at least the last 5 years, but there's never a chance to hang around. Last time on my own time was ~20 years ago.