I use the Sewer Solution device for draining my holding tanks. The principal reason is my trailer has a very low stance - great for towing stability but sometimes the CG sewer hookup is higher than my dump valves. Works as advertised, if not better. Retails for about $110. I've had mine for well over 10 years and it is still going strong.
Holding tank chemicals - I use a non-formaldehyde formula for the black tank, the sole reason being you may come across the CG that does not permit mixtures with formaldehyde to be dumped into their system.
Enjoy & safe travels.
