Re: Alternatives are good.
To try to deter deer, we once made our own pepper spray. 3 habaneros, finely diced, into an old perfume bottle filled with isopropyl alcohol. Let sit a couple days for the spiciness (capsaicin) to really dissolve well. You don't even have to pull the pieces out of the bottle afterwards. I sprayed just a bit on the railing of our deck, to see if I could smell it, and accidentally caught a whiff of the pepper-laden IPA vapor. Ugh. Good stuff.