I am not aware of any state that allows cosmetology services to be performed "in your home". When I went to cos. school

in 94-95 it was made very clear that you would loose you license for doing such a thing!
I live in Ohio....
4713-11-08 Resident salons and mobile home salons.
Except for beauty salons licensed prior to September 5, 1977, salons shall maintain a separate entrance which shall not open off the living quarters, and which shall not have any doors, openings, or any other access leading to the living quarters or residential areas. Entrance through garages or any other rooms into the salon shall not be permitted. Mobile homes, motor homes, trailers or any type of recreational vehicle are not designed for commercial use under the Ohio building codes and therefore prohibited for licensure as any type of salon or tanning facility.
and figured since the OP was from NJ I looked up their codes and found basically the same code. NO in home services.
http://www.state.nj.us/lps/ca/cosmetology/cosmoregs.pdf
now, if you are talking about a LEGAL salon that is a separate premise, then by all means, I would tip. I would not even go to someone that was running an illegal shop out of their home. Most people are not aware of the laws, and that is understandable. This was drilled into our heads during school

we are not allowed to legally cut anyones hair in our home except those who physically live in your household.