@h8bigbiz, I'm also a mouth breather and a few years ago I was considering septoplasty due to having a deviated septum and nasal congestion most of my adult life. After my Mayo ENT discussed the risks associated with the surgery I decided to go with his recommendation of a proprietary Mayo Clinic nasal spray which I used for a couple of months along with twice daily nasal rinse. My ENT thought my problem was due to rhinosinusitis so prescribed the nasal spray. After my second RX ran out, I continued the twice daily nasal rinse and it pretty much took care of my congestion issues with the blocked nasal passage.

The 3 ingredients in the Mayo proprietary nasal spray are Mometasone to reduce inflammation, Ipratropium to reduce nasal drainage and Diphenhydramine which is an antihistamine to help reduce nasal drainage. The product description on my prescription is MOMET 0.033% – IPRA 0.02% – DIPH 0.02%. I think an ENT doctor may be able to write an RX but you may want to talk with your doctor and/or give the Mayo Pharmacy a call for more info.

Since using the proprietary nasal spray along with a twice daily nasal rinse, I've switched to using the SinuSonic Sinus Therapy – https://sinusonic.com/. Each device lasts about 6 months and is about the same as paying for the twice daily nasal rinse supplies. I was surprised at how well it has worked for me. Here's a study that I found on the device prior to buying one. I've used one for a couple of years now and it has pretty much cleared my congestion as long as I use it once or twice a day. I normally just use it before going to bed.
— A novel device combining acoustic vibration with oscillating expiratory pressure for the treatment of nasal congestion:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7317541/
Hope this helps.