Teasing aside, this works surprisingly well. The default settings for dehydrate is 150°F, which is well under the glass transition temperature for PETG.
Would not recommend for ABS/ASA. I have no idea what temperature that plastic starts putting out its toxic fumes at, and I don’t want to find out.
Good question.
I’m kind of assuming the spool plastic has a higher glass transition point than the filament and can take the heat, and that any chemicals offgassed either vent out, or can be wiped away with a cheap 95% ABV spirit.