Ive ingested tea tre oil before. I believe its safe as long as its deluted and as long as you are using a high grade oil. I wouldn't use a cheap unknown brand or anything sold at Dollar Tree or Walmart, places like that. I've poured Melaleuca oil down my throat before and although it burned, it never gave me any other side effects that they list. However, use at your own discretion. I use a lot of alternative healing remedies and I am healthy and only take one prescription for asthma. I have deluted it tea as well. The Aborigines have been using it for centuries. "It’s been well documented that the Bundjalung Aborigines in eastern Australia have used tea trees to treat ailments including coughs, colds, and sore throats by inhaling the smell from the crushed leaves, and drinking an infusion of Melaleuca tea." https://www.youngliving.com/en_EU/discover/history-of-essential-oils/history-of-tea-tree#:~:text=Australian%20Aboriginal%20Uses%20for%20Tea%20Trees,-Aboriginal%20Australians%2C%20indigenous&text=They%20would%20use%20tea%20trees,cover%20it%20with%20warm%20mudpack.

Great tip -- will give it a try. I have some freesia oil in the house. I've found I can get a similar effect using Caldrea laundry liquid. It isn't super concentrated, a small amount does a good job of washing, and it both deodorizes and leaves a slight fragrance. They have lavender. I also like their Sweet Pea (though they market it for nursery) and Sea Salt Neroli. Currently I'm using the Palmarosa and Wild Mint. Their linen spray with the same fragrance makes bed sheets smell heavenly, too. Mrs. Meyer's is the sister brand.

I just remembered that when we were at that park in Louisiana I got online to find something to use on Mia to help rid her of the fleas that were on her that was safe. I found mixing a portion of apple cider vinegar with water and a drop of detergent in a spray bottle was amazingly successful. We set her on a towel, I sprayed her to dripping wet with the spray and we watched the fleas just float up and we would just pick them off of her onto a paper towel every one was dead. I had no idea that would work. We reapplied a few more times with in the next day or so and each time less and less fleas. So you might want to try that, nothing in it that would harm the pet. In fact I add apple cider vinegar to Mia's food daily as directed by her vet for her reflux. We were really amazed. Luckily I had everything right there in the rv to use on her immediately. Poor baby was just scratching like crazy, we did not let her back outside in that area.

I've made lemon balm mosquito repellent by soaking lemon balm leaves in witch hazel and then adding a few drops of mint or lemon grass essential oils. I can't remember the exact recipe right now. I made it last year. It works but not as well as deet. You have to apply it more often. However, deet is poison. Maybe try lemon plant and mint oils in your pumper sprayer.