CleanStart is the only registered product for controlling RR volunteers ahead of canola. It may be tempting to try other products, but these products are not registered.
Not only does the use of unregistered products violate the Canola Council of Canada’s Export Ready message, but it could also set back the canola crop. Canola damage from pre-seed applications from MCPA and 2,4-D, for example, is well known. The photos below show canola damage from a pre-emergence application of 2,4-D. The result can be purpling of the stem, stunted growth and in some cases, deformation. One seedling in the photo has no cotyledons and no growing point.
The whole point of controlling volunteer canola and early weeds is to give the canola crop a head start. But if unregistered herbicides are setting back the canola crop and thinning the stand, the whole purpose of a pre-seed burnoff is compromised.