The way things are at the moment i would steer clear of them and try to talk them into a regular thing,you`ll never make a good thing out of first cleans unless there on going afterwards your just making it easy for the next WC if you ask me.I never do first cleans these days unless there prepared to have it at the maximum of 12 weeks-3 months,get caught a few times and then you`ll know what i mean.