5c lipo charging (playing with fire?)

[mtbd500]

My gens ace and thunder power batteries are 5000 mah (5 amp) and the label claims they can be charged at 5c
5 amp x 5c = 25 amp charge rates!
Has anyone ever charged the cells at this amperage and are there any commercially available chargers that can charge 20 to 30 amps that do not cost several hundred pounds?
A 5000 mah lipo could potentially be almost fully charged in approx 12 minutes! So the runtime outlasts the charge time!.