heee, I didn't used to know about sealant guns either - we have 2 now though... Did you smooth the sealant over after (a bit of potato works better than a wet finger, but if you over smooth it it gets weak around the edges again, though it looks smart...) also we learnt the hard way when sealing a bath fill it with water so it sags, and leave it in till it's dry (else it pulls the sealant away when you fill it even though it seems fine empty)... also the sealant remover is strife and overrated... I'd go for stanley knife first, Then maybe sealant remover to tidy up, but it was slow and gunky and not overwhelmingly impressive...

I'm sure DIY's more fun when you're figuring it out for yourself!! :)