Also to add to above. incorporating 2 delte attribs to one dont make your stuff faster necceserily. Peopele often get hooked up by api is 1000 faster than mel... well thet not entirely true.
It has the potential to be, its not necessarily true in all circumstances. take delete attr, well after implementing undo and so on you will find you win only the time it takes for maya to find attributes 2 times, if you kow the explicit names not even that. So in the end youve just made a 10 millisecond job a 8-9 with 100 rimes more effort
Why because delte attri is using the exact same methods as you are. thus if you ask same methods your speed is equal. You only get a hoge bookkeeping task as a offset.