Hiya Becky,
Welcome back to planDisney! As a mom to a little Mouseketeer, I definitely understand the need for good health practices. I often travel with a small container of disinfectant myself, so I can sanitize surfaces she comes in contact with.
That said, Walt Disney World Resort has implemented
increased cleaning procedures since the onset of the pandemic in 2020, making the Theme Parks even cleaner than before. The custodial Cast Members are outstanding and always do a great job at maintaining the cleanliness of all the resort hotels and Theme Parks. I've always felt super comfortable at Walt Disney World. I went ahead and went through the Official
Walt Disney World Resort Property Rules and spoke to a Cast Member, and there is nothing prohibiting you from bringing in an aerosol disinfectant spray into the Theme Parks. Note that Cast Members reserve the right not to allow an item into the Theme Parks if they deem it to be a negative impact on the safety and/or experience of other Guests, so keep that in mind. My guess is that you would have no issue using the disinfectant on outdoor quick service dining tables, but if you are trying to disinfect attraction seats and holding up the line to do so, that would not be allowed.
I hope that was helpful, Becky and that you enjoy your visit!
Happy Planning,
Ashley F.