I'm still confused.. you see, I have been working with sets of 12-15 in the past and felt that I could do another set immediately without pausing.
Now I'm trying to go to near-failure with 6 reps which is in the strength range, rather than endurance or mass growth, right?

There are 2 things that strike me..
You tell him to only work out every 3rd day.. I work out 4 days/week, but do a leg workout (quads, hams, gluteus) on Monday and plan to do aquajogging (running in water) in the evening.
Tuesday is for chest,triceps, biceps, wrist, calves and abs
Wed for spinning and I try to not obey the orders to use heavy gears but spin light instead!
Thurs for back, shoulders, abs
Friday is light cardio day: a light swim or a bike ride..was thinking of riding up and down a small local hill (there isn't much choice here in hills , it's only 30m)
Saturday is depletion day.. I'm on a ketogenic diet with carb loading on Saturday: start with spinning and then do 1 exercise of 12 reps for each muscle group with exception of hips, calves and abs for which full sets will be done.

What do you think?