Please stay on topic, thanks.

It is true that police do not need to obtain a warrant to enter your home if they have probable cause to do so, such as you open the door during a knock-and-talk and they see a bong of the coffee table. They do, however, need to go back and get a warrant to do a proper search of the rest of the premises, which they WILL get, based on this probable cause. They can tape off the house during this time and not allow the occupants to re-enter until the search is complete.

There is a saying that holds true as much in growing as in poker, where it originated:

If you can't walk away, you shouldn't play.