Initially, I started the process using 'Owatrol Marine Strip', which was not very effective. In fact, it had these large crystals in it which just didn't seem to dissolve in the solution. I assume it was undissolved caustic soda. Anyway, it didn't perform very well.
For the next round of anti-fouling remover, I tried 'Strippit'. Ironically, this was actually cheaper than the Owatrol. There were no undissolved crystals in it and it seemed to manage to remove 3 to 4 coats of anti-fouling paint at a time. Nowhere near what they claim it will do but a dam sight better than the Owatrol Marine Strip.
I ended up using 2 x 5 litre tubs of the 'Strippit' in addition to the Owatrol. Not an awful lot of fun, especially trying to do the section that butts up to the keel. All in all, I must have removed at least 10 to 15 layers. I have not quite got back to the gel coat but as Genesis is a gin and tonic cruiser as opposed to a racing boat, it will have to do.
One thing I will say, is be very careful not to get any stripper on your skin. I managed to get a small amount on the inside of my knee and it burned like stinging nettles and I have a lovely looking red patch left as a result.