I doubt you will buy any lead bullets that arent lubricated somehow.
0.358 is the minimum diameter I would use in any 357 caliber firearm.
Undersize hard bullets going too fast are the main reason for fouling.
Hard cast sounds like its great but it isnt.
You need bullets that are at least 1 thou over bore size.
I use home cast bullets sized to 0.359 using lead that isnt hard.
A correctly matched bullet to your bore kept below 1500fps will work fine.
As they have done for the past 150 years.