How to strip miniatures? An old chestnut of a question that pops up on many a forum or facebook page. I have tried quite a few methods down the years. The most hazardous (and also least effective) was brake fluid and dettol. I had better success with Simple Green, though that method requires a day or more of soaking and is not that good for plastics. For me, the best all round performer is Biostrip 20. It works on metals every time and does a pretty decent job on plastics too. It's not toxic, so you can safely wash it down the plughole. It's kinder to skin than the others too, though if you are using it for a long session of stripping many minis I would suggest latex or disposable gloves. It's also easy to obtain. In the UK you can scour ebay or just google for online retailers, including amazon if you don't mind using their service. It's around £10 or £12 for a half litre tub, which will strip dozens or even hundreds of minis.
The first step is to cover the mini in the stuff. You can just dunk the mini into the tub of biostrip, shake off the excess, then pull it out and put it to one side. Or just dab on with an old brush or toothbrush. I have some large nylon bristle brushes that I picked up at one of those discount stores, which I use for jobs like this, for making and painting terrain, that kind of thing. I also have an empty plastic tub in which to put the minis for a short wait, an ice cream or margarine tub would be suitable. Then it's just a short wait, around half an hour is usually sufficient.
The next step is to rinse off the biostrip. Get an old toothbrush or nylon bristle brush, give the mini a quick scrub, then continue to scrub away while holding it under warm running water. That should remove most, if not all of the paint. Particularly stubborn paint may need a second application of the biostrip and maybe a longer wait coated in the stuff. As you can see in this sample, the mini is pretty clean at this stage, just a little left in the deeper creases. It's these final bits of paint that are the hardest to remove. I use a wire brush on harder metal minis, though I would be hesitant to use it on the older, softer pewter figures, or plastics. Another option is to carefully scrape away any paint flakes with a pin.
When you have finished, your mini is pretty clean. Another buff with the nylon brush to remove any flakes and it's ready for priming. I have had a good success rate with this method. It's quick and easy, it's non-toxic and it's reasonably priced.