That’s better. Ideally move them into a bucket or more of sand. I don’t know how it would work for batteries, but explosives get more dangerous when put in a container. Sand is better because it can absorb a lot of thermal energy without catching fire. Any non conductive non flammable material like that should work.

Also I’m not an expert on this stuff. Go find and listen to one.

The bulging battery on its own isn't (much) more dangerous than a normal one. The problem is once the device splits open, the battery is no longer protected and much more likely to get accidentally punctured. A regular battery combusts when punctured, and the bulging battery would vent that gaseous content (which IIRC is Hydrogen) and then combusts, which makes for a larger initial fireball.

I used to deal with puffed batteries a lot and went through some basic training on safety and how to ship devices with them for repair. We only ever had one battery fire, it was a from a normal battery, and it happened when someone shoved a t-pin through the headphone jack of an iPod touch because they thought it was a reset pinhole.