I’d assume the little keychain button cell ones they sell at pet stores would be ok. As others have said, avoid too much white walls until the battery drains a bit.
But if you have a thrower with a small hotspot, those work great too!
I can recommend the Noctigon K1, and the Manker MC13, both with CULNM1.TG. I have used both with cats and they are definitely safe (obviously as long as you don’t shine directly into the cats eyes). I use them on moonlight or low-medium and they work great even during the day. Mine are white but you could get a colored one which might be fun.
Though I guess all cats are different so YMMV but I can confirm 2 black cats go nuts over them and even seem to prefer them to a laser.
The MC13 is slightly better I’d say because of the TIR. You can get the 18650 tube for it too.
1mW is fine. The regulations say 5mW is safe for general use (dont point directly at your eye though). As you’ve mentioned/complained, it’s rather difficult to find actual low power ones now. Try a dollar store maybe?
If you want to feel better, see if you can either get one with a focusable (defocusable) beam and make the dot bigger, or scratch the lens to diffuse it…
Some come with “fancy” add-on things that make little pictures like butterflies or whatnot. All of these spread the light output over an area, degrading the power. Basically you just don’t want a tiny dot.
Most of your boardroom & classroom laser pointers are like 1mW. I have a certified 4.67 green laser for star gazing, pointing out constellations and such. Your classroom pointers are fine for cat toys. Just use it with some common sense. Frogs and Toads like them too. They think they are bugs and try and attack the dots… pretty funny
Lasers and pets, a small anecdote. Took my red pointer over to a friend with two Rottweilers. They played hard and had fun, but when it was over one of them couldn’t let it go, and now goes nuts at every specular highlight it sees, inside or out. Chrome bumpers during a sunny day are a dicey thing, especially given the mass of these dogs. Take out your knees in a micro-second. It re-wired its brain somehow and turned into a real problem for the dog. Anyway, I no longer let animals play with laser dots. Sometimes when I see politicians on TV, I do wonder. Did their significant other recently have a pointer play day?
Cat toy lasers are always red, it doesn’t cause blindness at low power. There is a guy on YouTube called Styropyro who does some crazy stuff but is very knowledgeable about the dangers.