Even though Pokerus makes EV training faster, it's really not necessary, IMO. I've EV trained without Pokerus and haven't had any complaints about it.
Another way to keep track of EVs is to use the PP of one of your Pokemon's moves. If your Pokemon's level is high enough, it should be able to KO Patrat/Lillipup with a single use of a move. 1 PP = 1 EV (or 5 if your Pokemon is holding a Power Bracer) The same applies to just about any EV training spot. This method is recommended if the Pokemon you're training is at a high level compared to the Pokemon in the EV training area.