I do like the whole "pre PCT" concept, similar to tapering. Though, I'd modify it a bit! I think D-bol is great for tapering. A person could do a 6-8 week cycle and end it somewhat like this:
1-6 Test prop 100 mg eod
1-6 Tren ace 75-100 mg eod
1-4 d-bol 20 mg eod
week 6 Test prop decreasing doses eod (i.e. a shot of: 100 mg, 75 mg, 50mg)
Week 7,8 dbol in decreasing doses (i.e. 20 mg, 15, 10, and then 5 mg first thing in the morning the last week-ten days)
Then begin pct.
The test prop would be pretty much out of your system by the beginning of week 7 and the dbol in decreased doses over those next two weeks would give you a gradual decline in hormone levels, hopefully enabling your hpta to kick in a bit before going straight into pct.