The two things you'll be up against in the UK (and quite rightly so) are:
1) Lack of appropriate AOC - UK parachute operators have to satisfy the CAA that they are fit and proper people to do the job for hire and reward and it's absolutely right that they should have to.
2) Insurance - I would wager that the average non AOC operator would not be insured to cover any sort of barmy idea such as you propose.
What you are proposing is certainly unsafe and bordering on the ridiculous, for the same cost of an hours hire of a C172 you can carry out your dream with people who are professionally trained and qualified to do it, more to the point, you probably won't be breaking the law.