How disposable potty liners work

A liner is a bag that sits inside a potty so that what goes in it can be lifted out and thrown away without the potty ever going near a faucet.

When it earns its keep

Away from home, almost always. A potty in the trunk of a car with no liner is a thing you have to carry, full, to somewhere with running water. With a liner it is a knot and a trash can.

Overnight, often. Anything that means not standing at a bathroom sink at two in the morning tends to pay for itself.

When it is just extra trash

At home in daylight, with a bathroom eight feet away, a liner is a bag you are throwing out for no gain. Rinsing takes about the same time and costs nothing.

Worth saying plainly because the math on liners is not subtle: they are single use, and using them where they do not help is the whole of the waste.

What to check on the packet

Fit is the only real variable. A liner cut for a full-size potty sits loose in a travel one and slips down the side on first use, which is worse than no liner. Match the liner to the potty you actually own before buying a box of fifty.