I've used Dettol to good effect at stripping GW paints from plastic and metal miniatures, but I found that going at the models with a toothbrush straight after the dettol bath (I tend to dip mine for around 24 hours - certainly no more for plastic models) caused a lot of the loose paint to "smear" over the model and it became stubborn to remove. I found that after the Dettol soak I got better results by removing the loose paint from the model with a sharp instrument before setting about it with a toothbrush, and the whole job was made easier.
For plastic models it's also important to wash off the Dettol with very soapy water, as water alone will leave the model plastic "tacky".