I had to stop myself from throwing out some empty bottles I had from VapeDudes. Aside from not wanting to toss plastic, I figured they could be reused for my own DIY mixes.
I found this post on how to easily remove labels.
And this simple solution for removing residual flavor from plastic.
If your just trying to get off labels from the OUTSIDE of bottles. WD40 works amazing. At my work we rent medical equipment, chairs, beds etc. Nursing homes put all sorts of stickers on the equipment to label who's it is. WD40 is the only thing that works well to remove any sticky residue. Even works better then goobegone.
Im not one of those nuts who throws everything away after one use, but how many times do you think you could wash and refill a juice bottle before it breaks down? I have about 50-60 or so saved back for when i start my DIY adventures.
That is an excellent question, and unfortunately none of the plastic bottles I own (both purchased and from vendors) give any kind of indication as to what type or grade of plastic they are made from.
I guess it's something you'll just have to decide for yourself, whether the potential risk outweighs the associated costs.
Tea tree oil is a) expensive, b) smells to high heaven, c) will permeate and eat plastic and rubber. I tried putting tea tree oil in a glass bottle with a dropper once, the rubber on the dropper lasted a couple of weeks before it was all melty and sticky like rubber cement. The best non-scarry gunk remover I've found is Simple Green.