What could I add into the water when using a portable foot bubble bath machine?

Whiskey and Ice.

Seriously, I would do Epsom Salts.

^^Kinky! For people with foot fetish.

Peppermint oil, lavender oil or tea tree oil. Or possibly all at once.

Epsom salts for the magnesium boost.

Depends on what you are looking for. If you want relief from soreness, Epsom salts are the best. If you want fun and relaxation, a lavender bubble bath would be nice. You can buy something like that in any CVS or other drug store. If you want to soothe dry skin, a bath oil with aloe in it followed by massaging in some moisturizing cream would help.

I use lavender epsom salts or small bath bombs.

Baking soda.

Cabernet Sauvignon or a nice Bordeaux if you have company.

Oh you were serious? Epson salts and lavender, of coarse :)

Is it a Foot Bubble Machine built for more than one?

If you use your imagination there is ;)

@Forever_Free Just for one person.

^^ There’s always room for a close friend.

Check the directions to make sure it doesn’t warn against certain products. If it actually has tubing and a motor to create bubbles it might say don’t add anything that can clog the tubes.

^^Oh yeah thanks!

@Forever_Free One foot in each? Oooo…

Palmolive?