Hmm. I was thinking you were wanting to sandblast Yeti's that had a colored powder coating. If that is the case, then you can use the cutter to create a mask so that only the cut out design is etched away. Bare stainless is a different beast for lasers.
How very unfortunate that your laser engraver met it's demise via a sledge hammer. I personally own a couple of cutters, a sandblaser, and a laser engraver. I choose to laser engrave whenever possible, but it's so much easier. That being said, it really depends on the type of laser you had. If it was a CO2 laser, then yes, it does require a light coating of some type of ceramic solution (although Dry Moly Lube works well too) that when heated by the laser, will bond to the stainless. But that's really if you're only doing stainless steel. If you're lasering the powder coated stuff, there is minimal prep of the Yeti - you just need to make sure it's clean. Depending on the power and speed, you can either mildly etch the coating, or you can vaporize the coating off all together. If you have a Fiber Laser, then it can etch directly to a clean stainless surface, without the need of any kind of spray.
As far as glass goes, it would be a similar prep that you would do if you were to sandblast. You'd still need to have some sort of mask/stencil.
Do you have a picture that was you're trying to accomplish?