Can you flame the top of a better bottle when harvesting?

I assume when using grain alcohol, that the flame will burn the alcohol and not the plastic but I'm not willing to chance my 6 gallon carboy to test this theory. Have any of you daring experts done this? Thank you for your help!

Why not just wipe it with some sanitizer? That's what I've always done with any fermenter when I harvest yeast.

I just siphon it out. If you're already siphoning the beer out, just stop at the end, swirl the heck out of the slurry and remaining beer, and continue to siphon. It may be difficult without an autosiphon though. I typically pump the autosiphon to keep the sludge flowing into my collection container.

I do the same thing as bobby_M but with c02 pressure and a racking cane.

If you aren't set up for that and don't use an autosiphon, I would just do what Denny suggests.

Better bottles at a fairly low temp. I have deformed one with a space heater in a closet (making a berliner weiss) and another on an automatic keg and carboy cleaner from the heat of the pbw (heat produced by the pump, my hottest tap water won't deform one).