Don't worry about it or feel guilty we all have these moments. You are in no way in the wrong in this situation and you are not a sick b*****d, the sick b*****d is the person who kicked and abused sunny- you are giving him a loving home.
I'm sorry I didn't explain the clicker properly- it's not a collar just a device which you hold in your hand and press. It makes a click sound. By, over time, pressing the clicker after you dog has performed a desirable behaviour and then treating him afterwards your dog will learn to associate the clicker with the treat and to associate the click ( which is associated with the treats) to the behaviour therefore giving him motivation to perform the behaviour.This proccess is called operant conditioning, they use it training dolphins as well.

Here are some pictures of clickers/ clickers in use:

Attached Images

	10_multi_clicker_unpacked.gif (52.2 KB, 1 views)
	250px-ClickerDogFxwb.jpg (23.3 KB, 1 views)

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Can it be used to associate it with bad behaviour also?

no do not use the clicker for bad behaviour, only for good behaviour when training!
it is completely different than the rattle bottle.

this website is really good, has tips and all about clicker training, it will be very beneficial to you: Fifteen Tips for Getting Started with the Clicker | Karen Pryor Clickertraining

Em i don't think so- at least not directly. It can however be used to reinforce good behaviours and prevent bad behaviours.
For instance, on this forum there was a thread about preventing/ teach dogs not to chase cars. What I adviced in the situation was as the owner saw an approaching car, to tell the dog to "leave" the car and then click the dog just as the car past at the split second before he/she started to chase. I would then treat and praise the dog. Repetition of this proccess would teach the dog to leave and not chase cars on command and eventually all together.
Clicker training is more of a technique that uses positive reinforcement, i.e. rather than focusing in on the bad behaviours and punishing, focusing in on the good behaviours just before the dog would perform a bad behaviour. Does that make any sense. I'm not sure if I explained it well- i think I made it sound a bit over complicated there.
As Sunny can be a bit nervous, positive reinforcement techniques are definately techniques that I would advise you try with him rather than using techniques which put emphasis on the bad behaviours.
I hope this helps.
Here is a link to a site that has some info. on clicker training which might be a better definition that what I just wrote:
Clicker Training - An introduction to clicker training

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Just took sunny for a walk

And wow.

Hardly no pulling on the lead, stopped sniffing at half the usual time, practised his name calling, did a bit of running. Real big change there tbh!

Yay! Well done both of you!

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