As mentioned above, are you adding water to the bowl before use? Many toilets you lift the foot peddle to add water to the bowl. Others, you depress the foot peddle half way to fill the bowl. In either case, this often helps with the flush. Some RV's have a side sprayer which can be used to rinse down the bowl. We keep a small toilet brush on the side or behind the toilet in a clam-shell type holder. As for a cleaning solution, any soap that is handy...409, dishsoap, windex. When you write about toilet chemicals, it really depends on what you use. If your using a biological product you need to be concerned about chemicals that stop the digestion of waste. If your using the formalin stuff, soaps will not matter.