Are you talking about damage to the silicone mould? Or the tackiness you get with clear-cast polyester?
Spray mould release works fine with me - you really need to leave the polyester in the mould for as long as possible, hours really to reduce tackiness.
I've also mixed a small amount of styrene with the clear-cast resin, which can give it a very slight milky look - but after polishing thsi seems to disappear. Huge benefit is almost zero tackiness and you can release from the mould after 30 mins no problem.
You'll probably only get 25-30 pulls out of the mould before you need to look at relining it. I know you are supposed to be able to 'cook' silicone moulds to redistribute the oils (or something) - doesn't work for me. Just get brown stained moulds that smell like they've been cooked. Maybe the ancient Baby-Belling had something toi do with it.