only forever same animals

I have a business in a very busy location. In my business I have two small trees that I have to wear every night in my business.
Because these trees were repeatedly marked by dogs, I bought this remote holding spray.
Basically, the spray works quite well, I think - but only under two conditions:
- They sprayed the Hold Off Spray often on the affected areas. But at least after every rain.
- These are the same dogs that come. This then obviously not learn to highlight here. In my shop there are unfortunately so other dogs and as soon as the spray is always not very new / strong applied, is marked again.

So for me, unfortunately, not very satisfactory.