Should come with instructions on the tin I would think, I've never actually done it myself but I read up on it a while back. I have a high idle on my 32 post engine build - I had the intake paint stripped / cleaned, and suspect in that process the factory seals are now leaking a bit.
From memory open them up, brush the stuff on, close and leave it to dry with them closed and it will form the seal.
So you still have the factory coat in place yeah - you didn't scrape it off or anything? Elec contact cleaner is really gentle. You might be fine but me personally I would do the throttle coat, easier than pulling the manifold off again.
Will have to do mine at some point when I can be arsed pulling it apart.