Either 45 days or 90 days is certainly not long enough to get them in treatment. If they're willing to enter a community-based treatment program and it's a community-based treatment program that has evidence that they know what they're doing, then that seems to me to be quite satisfactory.
As Mr. Fletcher said, what evidence there is suggests that community-based programs are slightly more effective--it's a pretty small difference--than institutional programs. What Corrections Canada does and what the Ontario provincial correctional service tries to do is get them started in treatment in prison and then have that treatment continue when they're released into the community. Over the years, Corrections Canada has funded community treatment programs and has carefully selected them so they know what they're doing.