ORIGINAL: Roskoe
I have heard the same thing about mixing bore cleaners. I can tell you that, from years of experience, that using Shooter's Choice in conjunction with Sweet's 7.62 is OK - and I generally use the Shooter's Choice to clean out the Sweet's after it has been in the barrel for 15 minutes or so. Any other combination is rolling the dice, IMO.
I always run 2 to 4 patches through the bore, to get whatever cleaner or solvent, I used, out, before I start using the next solvent. However, never mix solvents in the same barrel.