Do you believe that is an achievable outcome?
If you (leading a FO) are "done" with Wallner, find the best trade offer you can get. Because if you take him off the 40, that means passing him through waivers, and some bottom feeder team will gladly take him off your hands, leaving you no return at all.
Even "cash considerations" will be better than nothing. It's what the Twins did in discarding Matt Bowman, as they apparently found a couple of teams interested in claiming him and gave the Diamondbacks a chance to jump the league's priority line to get him. Wallner has more trade value than Bowman, surely.
But doing that is not "briefly." It means washing your hands of Wallner entirely and forever.
I'm fine with anyone stating nearly any opinion about what should be done with Wallner. Simply cut him, if that's your view and you want to defend it. (I happen to value him more than that.) But "removing him briefly" from the 40 man is about the same as Colorless Green Ideas Sleep Furiously, don't you think?