Try it because unless you...
1) use a much lighter load then you plan on
2) take a lot more rest than 15 seconds between sets (30s at least)
3) use shitty form to decrease muscle tension to be able to get more reps (which would of course be counterproductive)
... there is no way you make it even halfway to 5 minutes. NEVER try to invent something in your head. Invent something in the gym. See if it feels good and then analyze if, based on your knowledge, it is a good method to use or not. The way you presented it, unless you are mega slow twitch dominant and used to super high reps, it's not even possible to do.
See it might be a setup that works for conditioning exercises. KB swings, sledgehammer striking, box jumps... but with isolation movement the pump will become way to intense (which also inhibits muscle contraction) after a few sets, preventing you from continuing. And on exercises like the squat or deadlift the form would break down and endurance would also become a limiting factor.
For the purpose you mention I don't dislike the idea of doing sets of 5 with a 8-10RM with 15-20 sec of rest. I used such a method myself (5-4-3-2-1`, also did 4-4-3-3-2-2-1-1) and "hard 5s" (3 sets of 5 with 20-30 sec of rest). But your theory is not well thought out. You should start by trying to do a few sets of 5 reps with your 8-10RM with 15 sec of rest and see how many sets you can get. The 5 min limit is arbitrary and unrealistic.