Can we add our own deodorizer puck to a rented porta potty?

A camping puck usually won't hurt anything, but call the rental company first and ask what they charge the tank with, because some camping formulas don't play nice with the blue chemical they already put in.

When we had a unit on a bath gut last year I asked the driver the same thing. His take was that most pucks are fine in a holding tank, but the ones with formaldehyde or a heavy perfume can fight the deodorizer they use and just make the smell weirder, not better. He also said the bigger issue for two people is not chemical strength at all. By day five the charge is just used up.

What actually helped us:

• Keep the lid down and the door shut so the vent stack can do its job.
• Park the unit in shade if you can. Sun on the roof bakes the tank.
• Ask them to add an extra charge of chemical at the service visit, or move you to a midweek pump since your reno is running long.

We went to twice a week for the last three weeks and the smell problem basically went away. If you do drop your puck in, tell the driver so he knows what's in there when he pumps.