I really have no idea why people insist on this "dipping" - What is the point? The travel bug hasn't got there of it's own accord (you know what I mean here, though it sounds a little silly) and hasn't actually resided in a cache for others to find and move so why do this?
As a cache owner it frustrates me that trackables appear in my listings (under trackables history) and show TBs or coins have been there, when they never have (especially for containers that are too small to house them anyway).
As a TB owner, I'd be pretty annoyed is someone started dipping on of mine, as I believe it is not in the spirit of moveable trackable items. If you own the trackable, I can't see the harm in it - except as a courtesy you should contact the cache owner for each cache you decide to "dip" into as it affect them as well as you. I've had people email me because they find caches that have had trackables logged into, but then they find they cannot fit theirs in there, also makes nanos harder to find because they are expecting/looking for something that surely must be much larger.
I think some people try and clock up the miles on their trackables like it is some kind of competition (it isn't, is it?) by dipping but in reality it makes little difference, large distance moves typical of travelling cachers moving TBs from one area to another are going to make a bigger difference anyway.
I think if you are insisting on dipping then you need to prove the TB has actually visited each cache, perhaps by taking some photographic evidence rather than a TB sitting in a car for weeks as the cacher gets out and makes finds.
In closing, I think there spirit of trackables is to share with the community, and that you shouldn't log a trackable into and out of the same cache unless it has been there for a while (days or weeks). Give others the opportunity to share it and move it. Find a trackable, help it achieve it's goal if you like, move and log a trackable, leave it for the next finder.