You are not required to have Tenant permission.I recommend an inspection after 3-4 months and again a couple months before offering them renewal.I do not recommend trusting the Tenant because it's too easy to hide something under a piece of furniture, not take a picture of the broken window or missing screen, and you can't see odors or extra tenants or unauthorized animals.If a Tenant refuses to allow entry, that's a lease/law violation and should be grounds for termination of the lease and removal of the tenant.

So there are no other complications like odor etc..

The carpet cleaner told you there is no odor in the carpet.

The odor is literally smoked into the lumber building materials.

It saves me the cost of a turnover and if they have lived there for any length of time the pet "damage" (odor, hair, scratched up doors etc.) has already been done.  

But the mass media was so enamored with him, his excretement had a pleasant odor to them.

I don't know enough about vaping to know if it would leave behind a residual odor. 

I believed their lies that the strong odor was due to detergent used in carpet cleaning.

Grumbling to ourselves, we let her out of the lease and lost a month's rent. she agreed to use security deposit to pay for the pest control.

Property doesn’t have any significant negatives (high road noise, power lines, hills, odor, etc.) 6.