don't use them in the actual dialogue, and you shouldn't have to really. use wryly/parentheticals sparingly and put them under the character above the dialogue. I think it's implied in that line, you don't need one imo.
and if you insist, I'm personally not crazy about "Re: anything" it just looks lazy.
if the brand was important to the scene, I'd probably just put it in the action line.
Jake holds* a box of Corn Pops.
Joe
Nah man, grab the Golden Crisp.
*"is anything" also usually looks pretty bad and doesn't read well.
This is all pretty much 101 shyt that I'm sure don't get nitpicked as much as I am, but why not skip the hassle? Also, i do this, but some hate it... if you really want to highlight the cereal, you can CAPS CORN POPS. That's supposed to be the indicator for the eye. "Remember this, it's important." but if it's not integral, don't caps it. I usually only do it for items that will play into the plot or have a callback later. It's kinda smacking you in the face with it "look at this!!!" but i like doing it. Despite some saying shyt like that is "distracting" I like seeing the occasional CAPS, italalicized word, underlined word, etc.
Now if you'll excuse me, I have to get back to not writing anything.