EV Training Via Join Avenue

I would like to EV train my in-game team (this is post game now), but i am too lazy to go subway grind for those power bracelets and such (i only have the HP band so far).
Apparently rich people can use Join Avenue to EV train their pokes, and also to clear EVs.

How do i go about EV taining via the Avenue? first i need to clear the unwanted EVs from my team, accumulated over the course of the whole game in battles. the Groomer clears EVs somewhat, but some berries do it too right? how does the mechanic with berries work? how does the mechanic with shop services work? will they say it has no effect on the pokemon if the EV values are already wiped to their lowest?
and then to gain the EVs i want i can use my Training shop and my two restaurants right?

help would be appreciated. i know its a lot of questions, sorry.

thank you for the info, it helps! I'll be able to check how much the services wipe or give on the tables located on serebii's website.

I'll also have to do my best to keep track of the numbers on paper too to avoid losing the berries or money.

as far as the berries go, the only places to get them are that one random woman who sells some for $200 and the dream world farm right?

Also when i do the shop wiping and training I'll let you guys know what the shop keeper's say when things are fully cleared or fully maxed out.

i checked my florist and they dont sell the EV clearing berries yet I'll have to upgrade even more)

I successfully EV trained my Darumaka though. now it has 252 in Attack and 252 in Speed and something in special defence...

So here is what they say:
When an EV clearing berry can't wipe anymore EVs it will say that it has no efffect (and you will not use up the berry)
Also a shop will say "but it's already strong" and not take your money if your poke's EVs are maxed out in that one stat you're EV training.


EDIT:
THE GROOMER IS A BLOODY RIPOFF!
its only real use is to quickly gain happiness. total rioff for EV training since it refuses to do the service if you poke is fully happy. (your only option then is to use bitter healing meds to lower happyness and THEN use the EV wiping service. lame!)
Here is the thing that annoys me the most about the groomer: if your poke isnt at max happyness, it will preform any of the EV wiping services even if the EV is already wiped out completely. THEY DONT TELL YOU ANYTHING AND JUST TAKE YOUR MONEY. so in order to be sure that your EV is wiped, you still have to have berries and use those >:[
In conclusion this service really focuses at maxing the happyness of pokes and will steal from you to make that happen. no good for EV training since there is no communication from the shop keeper about that. NONSENSE.

I think i'm going to replace my groomer with another training facility.

(perhaps its only worth keeping if i level it to lv10 and then do the bitter medicine trick to just erase all EVs in a stat at once. that way it should be guaranteed hmm...)

yes i knew that, thanks! $200 is the best deal in this game. wish she sold more.