I think you will find not many people on here will approve of these
Although some people say it is not an unkind method it is definitely
not a positive training method. Anything which frightens the dog or causes something unpleasant to happen when they behave in a certain way is a
negative method and therefore not something I would use tbh. Positive training means giving praise and rewards for the right behaviour and
ignoring, not punishing the wrong behaviour!
I find that a simple Uhuh or a distraction is usually enough to interrupt unwanted behaviour
If it is just for the trouser problem I would probably persevere with distraction with a toy or something and if that doesn't work use time out. Try and be patient, although it may not seem like it at the moment, it is something he will grow out of in time. The first few months I had Coco, all my trousers had teeth marks in but suddenly I realised that she hadn't done it for ages - hurrah!
Hope that helps!