Thanks for the reply.
Watercolours are also risk-free, but I take your points about graininess and inconsistency. They will work fine on one model, then the next one will be a mess. I've also found that artists' watercolours seem to come off too easily, and you take off much more than you wanted to. Sometimes I've had to rewash areas several times trying (and re-trying) to get it just right.
In my experience, the wash phase has been where many of my best paint jobs have gone to die, whether by oil, acrylic or enamel. The ability to remove it is a definite selling point, and why I never abandoned watercolours, as problematic as they could be. Anyway, I've ordered some Flory washes (Dark Dirt, Mud Brown, Grime and Sand) and I'll see how it goes.
Thnks,
Ken