you could, but in order to avoid exposure to the chemicals in scotch guard I would recommend wrapping your mattress with an encasement cover instead. Here is an example of encasement covers that Coast to Coast Mattress offers at a great price

Hi Derrick, I wouldn't bother. Scotchguarding wears off and it's important to keep your mattress free of stains, as a stain will void your warranty. Instead, use a waterproof mattress pad. It doesn't need to be a zipper on type, a fitted one will do nicely. First place to look...TJ Maxx or Marshalls. Bed Bath & Beyond, if you can't find it at the other stores. By it from a mattress store, and you'll pay too much...usually.

Scotch guarding is a great way to add toxic off-gas to a mattress. Encasement covers don't prevent off-gas, although they can be resistant to bed bugs. Get the mattress with the most organic and/or eco-friendly components. Same with any mattress protector. Off-gas comes free with memory foam. The covers or sprays are to keep stains from setting.

Organics wont prevent bedbugs. And sprays void warrantys. Just get a waterproof mattress pad. Some places offer gurentees that will replace your mattress is zpills get through. The only way bedbugs get i to your mattres is if the store stores old beds in the same places as new beds or if they hide in your luggage if you go to a low quality hotel. They just dont appear there in their own.