5 minutes can feel like an hour with freebase.  It happened to SWIM's friend the first time she smoked it.

The most important thing is to go in with respect, whether brewing or smoking, by which I mean prepared for the potential that it might be the most intense thing that has ever happened in your entire life, intense beyond your current understanding.  That's why people are saying to start low with the mimosa/rue... because it's a long time to be struggling with something that you weren't psychologically prepared for.

SWIM started with 12.5g MHRB and 5g rue (although probably lost some due to unnecessary heating), but was prepared for an experience of divine magnitude... and got it in all its beauty.  His second time, he went in casually just wanting fun, and got burned, it was horrible.  Go in humbly!

If you go in flippantly, you may well have a horrible time.  But if you go in fully aware of the potential magnitude of the occasion, you're likely to have a good time.  Enjoy