A course or programme of six months or less can be done on visitor status, with no study permit at all. That part is true.
What usually goes unsaid is the other half. On visitor status there is no right to work during the course. And if you later decide to continue into a longer programme, there is no shortcut: a full study permit application still stands between you and it, and you may have to apply from outside Canada.
So allowed and wise are two different things. Plan the whole journey, not just the entry. If the short course is really the first step towards a longer programme, it is usually better to apply for the study permit for the longer programme from the start.
Current rules are always on canada.ca.
This is community experience, not legal advice. For your own file, speak to a licensed consultant or lawyer.