Cheers folks, was thinking about bleach, was thinking of something a little more toxic in the long term though, might give that a shot all the same.
Done big job with french drainage when we got here, basically sitting on a spring, been looking to get some concrete moulded ones to put grids on for the other end, but never found any for very cheap.
Improving the airflow further wouldn't be worth it, no rust issues now.
I cemented in the doors from water ingress, never opening for multiple reasons, drafty enough as is,and no insulation in the workshop which would likely make matters worse, if I had.
Keen to keep the clutter in the way for lots of reasons, rather than making the place that much more draughty.
Thankfully I don't have that much ply, a saw vice, bit covering the TS for jigs sometime, log sled for the bandsaw, and a lamp base.
Be easy to chuck a layer of dust on top to keep from happening.
Don't plan on having too much of it around apart from the odd jig.
as it won't grow on the toxic timbers I have
Only on the wee bits of green timbers drying is what it likes.
Still pondering about a coating of something, but wouldn't want white gloss paint flecks on some stuff like sleds, like with shelves.
Would like a clear finish on some of the ply, and something that penetrates rather than wearing off.
Linseed seems a bit 'natural' to me, maybe clear coat of 'non edible' lacquer might be a half ar5ed solution, but seeking something more permanent.
Thanks folks
Tom