When can tenants refuse the 24 notice?

[Jackie Sladky]

We have tenants who stored flammable items in their unit, in violation of the lease, and removed them when told.

Six months later there was a leak in their unit and when the handyman came it to fix the leak, he informed us that he saw the flammable items back in the unit. Do they have the right to deny entry when we give them a 24 hour notice to enter for inspecting the place to ensure that they still do not have no flammable items?  That is, they can state that the request does not have valid reason and that they already removed the items six months ago.  These are hard to work with people that we inherited from the seller, and we still have quite a few months in the lease to go with them.