xargs utility on Mac is not the same as the one on linux. In particular, searching for files with the
mdfind utility will not properly escape files to be processed.
homebrew you can install the GNU version of
gxargs, and you can use the syntax you’re accustomed to from GNU/Linux.
For me this is equivalent to something like:
mdfind -name "conflicted copy" | gxargs -d '\n' -P 4 echo
To remove the files you can then replace
rm – but be careful!