[k9mkt]

Am seconding Brent & Spilt on this. I've tried many types of solvents and cleaners over the years. Some do work yet some made it worse. I hardly use anything these days to clean the damages. But if you're in the market for something, you can try the X ... from Gt .... seems to work.

Repairing long cracks is a personal preference. I however, am not keen in doing so though i've had quite a bit of success in arresting these long cracks and repairing them in the past. As what Brent pointed out, I've done my maths and found out that I made more by repairing all the 'other' types of damages. My competitors loves me for this reason and have had some referals from them too!