I guess it depends on what your protocol is, for what goes into the bowl, but for anything other than liquids, I think that time just makes everything else harder to deal with. My wife was always in charge of the head, and she was very particular about what chemicals were used. We pumped in the ocean, and the only thing I ever saw was a stream of blue liquid.
My previous boat with a Vacuflush was a 30 footer, with a good sized holding tank. I bought it from a guy who kept it tied to the dock behind his house, as a getaway man-cave to drink beer and watch TV. He did nothing to his holding tank, what went in came out. The first time my marina had it in the shop, someone working around the helm hit the discharge switch without knowing it, and as luck would have it, it was an on-off switch, instead of a momentary. Everyone started yelling at him, but he couldn't find the switch until it was pretty much on the garage floor. I wasn't there, but it took me a while to smooth that one over with the guys in the shop.
I did install a momentary switch right away.