is engine oil stop leak any good , if my crank seal is leaking would this help stop it?

Why is this in the spotted section?

An no it's not any good. Get the seal replaced along with the cam belt if it has been contaminated.

Also will depend on what is causing the leak. My previous car (not Skoda) had a crank seal leak and it was due to a worn (grooved) crank and after replacing all the seals and belt it leaked even worse and ultimately needed an engine rebuild to replace the crank. I even tried a 20/50 oil to see whether the thicker oil would stop/slow the leak and it made no difference.

Lol yeah I want to know why this was in the spotted section also, this could get funny/interesting... :p

Can cause more hassles in the long run tbh.