filament repellent paint

prevents sticky plastic buildup, easy to apply and dries fast, keeps your hotend and nozzle clean, fit for PLA PVA ABS Filament （PETG is slightly less effective）
Cool and apply. Once the coating is formed, it can be used. Once the coating is used up, it can be reapplied.

[@chaosvii9459]

This why you need use silicon socket

[@fysetc4882]

Yes，This is just a comparison of the usage effects. It is actually mostly used for nozzles.