If it is rinsed out really well, I would think that would be a great idea and save you money too. People use rocks in their aquarium, why not pea gravel too. Also it will have a very natural effect.
Theresa

You should be okay, but just to be sure, check the gravel first to make sure it's aquarium-safe. Dump a few pebbles in a cup of vinegar. If there's no obvious reaction (lots of bubbles) the gravel should be okay.

Some gravel contains a lot of alkalinity and can seriously alter the pH of your tank.

Your hubby has got the right Idea, now you just need to foreward the money you save to another fish tank.

Thanks guys. We went ahead and got the gravel. Should be washing it out tomorrow.

Hi :) I'm sure I am too late to offer any useful advice here, but first I would put all the gravel in a bucket and fill with water ... then watch for any oily film on top of the water after a half hour or so that would indicate the gravel may have been exposed to some kind of petroleum product. If it passes that test, there is a chemical you can get at most older family-style pharmacies called potassium permanganate that you should toss a couple tablespoons of into that bucket with the water to disinfect the gravel. After another half hour, you should pour that off, agitate the fire out of it over and over with a hose nozzle until the water comes out clear. Sorry so late! Hopefully, none of this was necessary, and yours turned out great!