Rubber Seal Restoration Repair Nitro RC engine carburetor soften old dried out rubber

I've been rebuilding RC nitro engines and come across a lot of old rubber seals. Replacing these rubber seals would cost as much as the engine if I could find them. I've been using this method for years. I use silicon spray and let it sit for about a week in a zip lock bag. Most rubber is not natural anymore and made from petroleum. If you need faster results use WD40 or PBblaster. Any heavy petroleum distillate should work. Sometimes the heavier stuff can weaken the rubber.

Silicon Spray
https://www.amazon.com/gp/product/B0019LV3GO/ref=as_li_tl?ie=UTF8&tag=fintechcomm0f-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B0019LV3GO&linkId=72932e2c9fe6936237257334bb1f6b47

PBlaster
https://www.amazon.com/gp/product/B000I2079E/ref=as_li_tl?ie=UTF8&tag=fintechcomm0f-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B000I2079E&linkId=ede07793ce2904a94bd23d935e141304