Scirocco Register

A set of front door seals have just arrived from Joost (thanks Joost!) so planning to fit them today. I started pealing the old seals off and they're attached with some kind of sealant all the way round.
Do I need sealant? Or can I just clean all the old gunk off the bodywork and push-fit the new seals without it?
If I need sealant, does anyone know what type please?
I don't think I used any sealant when I replaced the boot seal.
Thanks guys.

It's glue - I've used Evo Stik "contact adhesive" on my mk1 seals.

I did not bother using any glue to stick the seals back in the doors or boot as they are snug and if I need to they are easy to remove.