Most of the newer generation of anticoagulants are made to be for multiple feeding before death. Not so much for mice, but rats are known to of eaten baits, but not enough for a lethal dose to occur and the sick rat can learn what food made it sick. If it takes several days for the effect, it is unable to associate what made it sick, along with more of a probability that it has taken in a lethal dose of the product. Buying from a pest supply house is not going to give you stronger toxin, but the baits they sale are going to be made more for the rodents taste. The rodents have to eat it if a bait is going to kill it.
Lar