Bird Repellent Gel
There can be no doubt that this product is one of the most reliable deterrents of the common pest birds that is available on the market.
Manufactured locally from a petrochemical (Polybutene) base, the product is packed in to 310ml tubes identical to those in which one buys silicone sealants from the hardware store. It can be applied to anywhere that birds may roost, and the normal way is to lay down a bead of +-5mm diameter in a uniform zig-zag pattern, onto a previously cleaned, dry surface. One then sprays a special sealant coat over this, which lessens the amount of dust that may be absorbed into the product.
Polybutene is extremely safe, being classified as not toxic and non-irritant. In fact, the chemical can be found in a number of products that we use regularly such as Cling Film, Ladies (or Gents, I suppose) Makeup and Medical Adhesives. One of the reasons it is so successful is its property of remaining tacky throughout its lifespan, which creates a symptom of panic in birds when they stand on it, as they believe that they are going to be trapped.
This, of course, is not true and it is also not true that the product burns their feet. The mistake made by the original manufacturer of Bird Repellent Gel was to name it "Hot Foot", which as we all know is American slang for "Get outa here!". In a similar way, "Vamoose" has a similar meaning in colloquial American, so please don't worry about birds flying off with smoking stumps for legs.
The only real negative property of the product is that, over time, even though the sealant coat is applied properly, a certain amount of dust will settle on the product.
This is not a problem when applied inside factories and warehouses as it doesn't affect its efficiency, but it can be a bit unsightly if it is in a very visible place outdoors.