It may, at the same time though, a high, may be because you're high but it may also be that your insulin is slow, in which case it may catch up? When I did more of this, it was before I bothered having any clue about ratios or factors and used insulin like something I bought in the parking lot of a Grateful Dead concert. I think the greater efficacy of IV may decrease the factor although I don't keep track of anything enough to be certain that it works "exactly" that way. Sort of like with heroin, people get burnt out snorting it because it's not as cost-effective so they try shooting and it works a lot more powerfully.
I don't think that doctors will recommend it except in a hospital, where they put it into an IV if you have severe hyperglycemia they are trying to clean up.