Dose - 5 Methadone pills to kick heroin

[Nahbus]

SWIM and his girlfriend go on heroin binges that last about a month. They really don't use too much, and usually snort it. Anyway, they are acquiring 10x 40mg methadone pills to help them come off.
SWIM doesn't know the best way he should do this as he has never used methadone.
He was thinking:
Day 1 - 40mg
Day 2 - 40mg
Day 3 - 20mg
Day 4 - 20mg
Day 5 - 20mg
Day 6 - 20mg
Day 7-10 - 10mg

Do you think this will be sufficient? Is 40mg enough? Is one a day enough (I read that it lasts up to 36 hours)

He also has valium, which he plans to take after the methadone. Hopefully it will be a nice smooth transition from dope - methadone - valium - clean

Any suggestions for a better solution with 5 pills? will 20mg be enough for a full day? Maybe he can extend them a bit longer.

Any help would be great! SWIM thanks you all.
Thanks!