I wouldnt egg windows or shoot their dog as it might not look too professional in other customers eyes if they find out!
Worried about losing income by dumping the dross ?? .... if you struggling to get your money then its not really an income is it .... spend the time u not cleaning the dross by canvassing or dropping leaflets or do the 5 a side trick ... drop the 5 houses either side of a good customer with a leaflet before you clean your customers house.