When huffing panties using the cupped hand method, it is best to come up for air at times, otherwise a high and a headache may ensue. Same when you put them inside out over a pillow for a faux 69. I guess both are safer than using a ligature on yourself, if that is yer thing.

I have seen electric bongs that fill a plastic bag with smoke, I am thinking of marketing a device to be able to trap and store used panty scented air, so the over abundance of CO2 doesn't create these issues.