Property managers encounter many differing standards of cleanliness during property inspections, so it is important to educate tenants at the beginning of a tenancy on cleaning guidelines. Any cleaning issues identified during a routine property inspection should be monitored carefully so they do not cause any long term damage to the property.
As soon as a cleaning issue is identified it should be brought to the attention of the tenant both verbally and in writing immediately. If it is a more serious issue, then this should be discussed verbally with the tenant and followed up with a 14 day letter requesting remedy.
The Tenancy Tribunal is unlikely to terminate a tenancy due to a one-off cleaning issue, however if you can provide evidence that the tenant has failed to deal with cleanliness issues over a longer period of time you will have more success with a termination claim.
Read more on dealing with cleaning issues during a tenancy.