Nothing beats a supply of Victor conventional mouse traps and a supply of 'Skippy' to bait them with. Many years ago I used to deliver to Victor in Lititz Pa. Old factory in town, terrible loading dock but nice folks.
I buy the original Victors, not the ones with the plastic 'cheese' that are worthless. Just have to be careful when setting the spring bar or you'll 'trap' your fingers and it hurts when the bar smashes down on them.
I cannot put down edible bait as our cats will eat it or the 'loaded' mice and then the poison gets them as well and they are my wife's cats and a happy wife (no dead cats from mouse poison, means a happy life. Amascon has them in quantity, They even sell full cases of them for those that have a huge population.