I used some cheaper stuff from IPD one time, and got leaks. Same exact parts, same exact surface prep. Used the Volvo pink stuff before and after that one experiment, bone dry (and i had my 16V apart and back together maybe 5 or 6 times?). YMMV, that's just my single experience with the non_Volvo stuff, and 4 or 5 times using the Volvo stuff.
And just get the surfaces super duper clean. Rub the surfaces with your finger to find any little bits of stuff too small to see. And once they are spotlessly clean, make sure they are DRY of all oil. I used rubbing alcohol and multiple clean paper towels. That will remove the last vestiges of oil and make for a clean and dry surface.
Then I used small foam rollers to apply the sealer - sold for trim painting in home improvement stores. Maybe an inch wide? And put this on both surfaces. Not too much - even thought it's not supposed to harden in the oil passages and block them, no need to give it a chance to do so. Just a nice even thin coating on both sides. No need to hurry, but just move right along to slapping them together and snug them down with a fair number of nuts right away, across the whole thing. So you get a nice solid mating of the surfaces while the goop is still pretty fresh.
Then stick the cams in (some of the cam caps also help secure the top layer to the lower head) and snug up everything. I didn't bother using torque specs, but don't overdo it.
Then I'd usually wait at least a day or two before firing it up and running pressurized oil into that freshly gooped seam. Partially because I thin it needs to set up before oil pressure tries squeezing it out, partially just because there's a lot more work to get a 16V together from that point, esp with a turbo. Not sure how critical that wait time is.