Personally, I wouldn’t use sprays – because of the hogs. If you find where it is getting into your garden, or has a bolt hole, you could try planting mint around that. I usually fill in bolt holes and try to make them difficult to re-dig. I pour water down first to make sure no-one is in residence!
Other than that, if you feed birds, try to make sure that no food drops to the ground and chase the rat away every time you see it. You will find they are more sensitive to sound/movement, etc. than hogs so it’s sometimes possible to scare them away even if a hog is also present.
I have on occasions resorted to supervised feeding. i.e. only feed the hogs when I was around to scare the rat away. The poor hogs didn’t have food the rest of the night, but they wouldn’t have done anyway if the rat had been eating it all and squirreling it away somewhere. Hopefully if the rat doesn’t get any food, it will realise it might have better luck elsewhere.
Some retailers will say that those rat scarers don’t effect hogs. In reality they don’t know, as one manufacturer once told me. He also told me they cease to become effective with rats outdoors very quickly. He even said if you buy one ask for a money back guarantee that it will keep the rats away for a reasonable length of time.
I tried in the past, for a short while, putting a rodent scarer out during the day and one night forgot to remove it. I saw a hog physically flinch when it went past that area so my feeling is that they do hear them. Needless to say it hasn’t been out since!
Good luck. Hope you manage to deter it.