Girdling crabapple trees is an excellent way to control how much fruit they produce. My grandfather actually had a technique he used that would limit the amount of crabapples produced, and how much fruit they would dump on our lawn.
While my family liked the crabapple tree, it wasn't very much fun picking up rotted fruit. Choosing branches to girdle actually really helped reduce our workload. I suppose I feel a bit bad about choking off the nutrients to certain parts of the tree, but it just seems cheaper than removing a tree. Also, I know there is free tree removal in some cities, but I don't think we're that lucky.