A few tips.....

there's plenty of paint stripper style products and caustic sodas to choose from, these work well to soften paint and make removal very easy.... but stainless usually has a well polished finish and paint doesn't stick that well anyway, so it will "chip" off without major effort, the strippers and caustic just speed up the operation.

wire brushes are the go for the removal of silastics/duralac etc sealers and are easily the best for removing corroded alloy that's lodged on the shanks/threads of the bolts or screws, as already stated its more a question of "holing onto" the bolt/screw as its being 'brushed'...

to make life far easier and A LOT SAFER use a wire wheel brush that you can fit to a variable speed drill and secure the drill in a vice or similar..... lower RPM wont be such a safety issue with fraying wires flying off and the chance of the bolt/screw being caught by the brush and flung into the never-to-be-seen-again region of the shed is greatly reduced...

This also has another positive with a lower spinning speed and that's one not many are familiar with....
99.9% of wire wheels are made of HIGH TENSILE MILD STEEL wires... mild steel and stainless DONT play well together and if you use a high-speed bench grinder and push a bit hard the mild steel 'can' impart some of its atoms onto the stainless and once its refitted to a boat and you get it wet it WILL rust slightly.
High grade stainless is less likely to be effected like this but can still have that mild steel transfer, lower grade stainless (316 for example) will rust stain very easily once the wire wheel imparts some of its metal onto the stainless.

If your going to wire wheel the parts then get a brush specifically to suit stainless steel

Also.....
its called a bench grinder..... it WILL even with a wire wheel "grind" to a certain extent, so caution is needed as to the pressure you apply with the part on the wheel, push a bit hard or for a few seconds too long and the wheel WILL remove material for the part, and it WILL impart some of its wire onto the part...


above all

its better to loose a $2.00 5/16th bolt to the never-to-be-seen-again region of the shed than it is to have a single wire removed from your now blind eye or suffer the septic healing from that wire imbedded in a soft tissue area of your body, the question then becomes, is any of it worth the effort for a handful of 2nd hand bolts/screws
Don't get me wrong, you just have to balance the risk/reward of the parts value over personal safety and well-being, in my game its always a shock as to how many people will risk injury for something that's worth less than they will make in an hour....



cheers