Canada DUI Entry

Hi.
I have been told that it's a huge pain to travel to Canada with a DUI. I have been doing some reading and it appears that a drunk driving arrest or conviction makes someone inadmissible to Canada, even if they come from a VISA exempt country like UK or USA. I need to enter Canada with a DUI for business, but have been told it takes as long as 6 months to apply for "special permission" in the form of a TRP. This sounds a lot too ridiculous, surely there must be an easier way? Driving under the influence is a really common crime, and I find it hard to believe Canada bars every American or Brit with one. Can anyone give me some reason answers? Before I spend any money on a Canadian immigration lawyer I want to make sure that I'm not making a mountain out of a mole hill and wasting my cash. Also, I have been told that the 2014 Canada DUI entry rules have been loosened, but from what I can tell it appears to only apply to US citizens???

Thanks.

I should clarify that I'm not actually interested in immigrating to Canada, I simply want to travel there for a week... which falls under the jurisdiction of "immigration" since I'm a foreign national.

Cheers.

Just a follow up. I took advantage of a free consultation from a Canadian immigration law firm (for anyone interested it was:
canadaduientrylaw.com). After 10 years you are considered to be "rehabilitated" and can enter Canada again, but until then you need a Temporary Resident Permit. These permits can be good for multiple entries for as long 3 years, so it's not a one time thing... although the process is fairly complex (you have to write why you're not a threat to Canadian societ etc lol) and it's a pain in the butt paperwork wise.