You can buy the “official” Dremel wool polishing pads with mandrels from a home improvement or hardware store.
They twist onto the mandrel like a nut on a bolt.
The mandrels (mounting axles) don't go all the way through the pads.
Eventually and after heavy use, the pads will split down the middle or twist the center out and fly apart. ¹⁾

Dremil polishing pads mount onto threaded shafts 2)

The pads have a tendency to spin off the shaft.
You can also use the metal cutting wheel mandrel for the pads.
Add a small washer over the wheel attaching screw and snug it down against the pad.
It doesn't have to be real tight.

The mandrel is re-usable. You can save all the worn out and broken shafts from Dremel rasps and small grinding disks also.
Then, re-use them as a mount for the wool polishing pads.
The old grinding disk axles can be pushed all the way through the polishing pads and they don't split down the middle so bad. ³⁾

Once the pad is worn out, just install another one on it.
To make the pads last longer, you can use JB Weld epoxy to mount them on the shafts. ⁴⁾

For about the same price as you pay for 6 of the Dremil pads, you can order a big bag of 100 polishing pads (including a few mandrels) online (Amazon, Ebay and etc.).
They are the same pads, same quality, and last the same. ⁵⁾

Below are some wool polishing pads that were glued to mandrels.
The larger ones are the 7/8“ pads. They will last a very long time mounted with epoxy.
But you need to let them cure over night before use for best results.
The two smaller ones laying down behind them are 3/8” pads.
They are good for getting in tight places. ⁶⁾

Polishing wheels for Dremil type tools 7)

Loading too much polish on the wheel smudges and doesn't help you cut the metal.
Pressing too hard while working also gathers and compresses polish into the wheel.
Use this to unload excess polish and fine metal particles from the wheel and recondition the edge.

Wheel rake 8)