That is, if you're not a professional instructor.

Do you use one or the other of these dummy guns as part of your training? What do you do with them?

Not a dummy gun but a laser ammo cartridge in 9/.40/.45.

I use it both in conjunction with an app and just with the laser.

It’s great for training down typical areas of your home you are likely to face an invader as well as from a draw or storage etc.

As an instructor, a dummy gun is indispensable for teaching grip/stance to a group without worrying about muzzle issues. For home use, I don't see why you would need one outside of H2H/gun disarm practice. You could use one for retention shooting, but you can do that dry-fire as well.

A SIRT or laser cartridge gun would be very useful though as an adjunct to dry fire.

I use a blue gun to mix into our BJJ training a couple of times a month. I can always use more practice fighting with a gun.

I don't have a SIRT, but I do have a blow-back airsoft G19 that I use to train IDPA/USPA indoors.

I do PT with a blue gun.