Does pure capsaicin repel mice and rats?

Shawn Woods has been trying out different home remedies to repel rodents. A while back he grew some hot peppers with a scoville rating of 2 million (one scoville is the minimum detectable amount of capsaicin, the stuff that makes peppers hot). He mixed his peppers with grain to see if it would repel rats and mice, but it didn't keep them away.
This time, Woods bought some pure capsaicin crystals (16 million scovilles) to see if it would work as a rat repellent. First, he tested some of the crystals on his tongue, and it didn't have much of an effect. Next, he tried a tiny amount of the powder dissolved in vodka and it hit him hard.
He then soaked sunflower seeds in a very strong vodka/capsaicin mixture to see if rodents would eat them. He set a pile of them next to untreated seeds as well as seeds soaked in pure vodka. They favored the vodka-soaked seeds, then finished off the untreated seeds. They did not eat the ones soaked in the capsaicin/vodka mixture.