Most pyjama damage doesn't happen while you're wearing them. It happens in the wash, where they spends thirty minutes tangled around a zip, a bra hook, and something with velcro on it.
This pouch is the simple fix, and it isn't complicated. Pyjamas in, zip closed, straight into the machine. The mesh is open enough that water and detergent move through freely, so nothing washes less well for being inside it.
