Chlorox won't do much, if anything, helpful for the soil. As far as I'm aware, the dip is available only in commercial quantities.

If only it were that simple. Your plant is infected and you will no doubt break dozens of roots as you dig it up. This will leave dozens of infected roots exposing an infection into the soil while at the same time sending new shoots to the surface. The infection is likely already in you soil where it can remain for years. That's where it might have come from in the first place, for all we know. It might simply be endemic you your area's soil. It's a real pain in the ass. I know from experience.

The galls are actually the plant's response to the bacterium's presence in the past. Whether it continues to exist in your soil or not, I don't know. It appears very common and wide spread in the desert south west, perhaps other areas too. Supposedly, what is required is a wound at or below the soil level to permit the bacteria entry into the plant. Therefore, it would seem unwise to prune roots when planting or to influence a plant's performance. It would also seem very unwise to "cultivate" your garden soil anywhere there may be rose feeder roots as those "wounds" could, potentially permit any bacteria entry into the plant. Similarly, "companion plantings" might also be potentially damaging, particularly in established rose beds. Digging a hole, of any size, could result in "wounded" rose roots, providing entry to possible infection by the bacterium. And, what about gopher vole or mole damage to the roots? Moles may not eat the roots, but they do dig through them and can cause "wounds" to root tissue. There are instructions all over suggesting you remove and replace the soil from a spot where a galled plant has been removed, though if it's possible the bacterium exists in your soil, what benefit would there be to replacing that soil in that spot? And, could the situation be similar to that of RMV, where, though you've never SEEN symptoms, the causal agent has been present for a long time prior to the expression of symptoms? I can't give you absolute answers, but I do raise these other questions to possibly point out that, other than using something like Galltrol and insuring there will never be any damage to the rose tissues where they may become infected, there really may not be much, if anything, you can do to prevent galls.

Can we see photos?