I have heard of it but I don't think its a good idea.
1. The factory mainspring has more than enough power, install a lighter mainspring from Wolf, I did it on a PP, it reduces the pull some. Just test with user's actual ammo.
2. next, get a smooth trigger installed or round the edges of the trigger it has. (big, big difference in subjective feel of effort/comfort.) These were the standard trigger before the GCA of 68. I buy them off Ebay. If the gun is stainless, rounding is easy, anyway you can't buy a stainless smooth trigger.
3. get the gun smoothed by someone experienced with Walthers (the walther forum guys like Mike at M&M Gunsmithing who worked for 15 years for Interarms.
I would advise doing 1 and 2 first, see how it feels. They will not be expensive to do, 10$ for a spring, 30$ for a trigger + cost of install (which is fast and easy for this for any real smith.)
Honestly it's possible just the smooth trigger alone will do the job, I have Walthers with both and it's surprising the difference it makes. Eventually I will switch them out on all my blued Walthers.