Use of braiser for frying
Uh...NO!

While running some 'minor spillage' down the floor trap is not a big deal washing a large amount of oil down the drain would be BAD. As the oil cools it will form a solid clog that would be very difficult (and probably expensive) to clear. 

(there is no information about where you are from, so this may or may not apply to you...)

[In the U.S.] 
Local fire departments will allow for the disposal of waste petroleum products (like this or motor oil). 
Most restaurants which do a serious amount of frying have oil disposal services that come by and collect used fryer oil.