In my opinion the best for the job is "Biostrip20", in case you want to try something new.
It's not harmful for the environment (!), doesn't leave a horrible smell (like dettol), works fast and easy and it doesn't damage the models.
What I do:
- I put enough in a cup so that the model I want to strip fits in perfectly.
- I let it in for ~30min.
- I bring the model to the sink, turn on comfortably warm water and hold it under the water while brushing the paint away with a toothbrush.
- Done in 2min.
This works perfectly on any metal or plastic figure. But finecast could have issues.
Some things to watch out for:
- If you leave a finecast model in it for too long it will start damaging the material. For some reason finecast is fragile for this stuff. I still use it on finecast but only soak for like 15min and then see if the paint comes off already. I once left a model in it for 2 hours because I forgot about it. After that the plastic became flexible. After a week (!!!) in the fridge it became stiff again and luckily the model was saved, but it was a close call.

- You could reuse the same stuff over and over again if you pour it in a bottle and safe it. The liquid will become dirty but can sometimes work for like 3 'runs' in a row. I personally am a lazy guy and never reuse it, but many people do.
Only problem is that I don't know if it's available all over the world, but perhaps through eBay there's an easy chance to get it.