How about the chmod "-a" option?
find . -exec chmod -a "johndoe allow delete,readattr,writeattr,readextattr,writeextattr,readsecurity,writesecurity,chown,read,write,append,execute,list,search,add_file,add_subdirectory,delete_child" {} \;
It will remove all ACL permissions for johndoe on all files recursively from the current directory. (It will print errors for all files without an ACL, but it will still work on the rest of 'em). As you mentioned, you'll have to run this with "inherited" and "deny" as well.
EDIT: Here are tools that use ACLs on Mac OS X:
# cat has_acl.sh
otool -IV $1 2>&1 | grep _acl_ > /dev/null
# find /bin /sbin /usr/bin /usr/sbin -exec ./has_acl.sh {} \; -print
/bin/chmod
/bin/ls
/usr/bin/ex
/usr/bin/rview
/usr/bin/rvim
/usr/bin/vi
/usr/bin/view
/usr/bin/vim
/usr/bin/vimdiff
/usr/sbin/cupsd
/usr/sbin/kadmind
/usr/sbin/pkgutil
vi only reads & preserves the ACLs, the others don't seem useful, either. But there could be 3rd party tool. Maybe in Fink/MacPorts?