I have seen certain of these barrels retrofitted with plastic liners which can be quickly extracted and washed, removing the requirements of actually deep cleaning the inside of the barrel (barring leaks of course).
However, the price nearly quadruples for such a change. Perhaps it might be worth seeing if some enterprising tinkerer could mock one up.
Lord Rudolf Von Kreutzdorf of Ostcliff
Golden Rose Trading Company
OOG - Larry Wile (Marshal)