*If your spectators "have an idea" you are using gimmicks, you should not be performing yet. They are no aware of that term, this is known as "magician paranoia," which again only beginners generally suffer from.*
Speaking of TT's, i have had AUDIENCES claim i was using one. I have had audiences want to look at my deck of cards suggesting i am using a gimmicked pack, that they are in some special order, that they are one of those special packs a friend of their's has.
In the few times i have been charged with using a TT, i was not even doing an effect that you could do with a TT.
People don't always think like that. They know a method, any method, they will blurt it out. How many people here have been told they are using their sleeves when in fact most of us rarely do ? Even a card trick where there is no way sleeving would help at all.
Do i roll up my sleeves before i perform anyway just so that idea cannot pop into their heads ? Yes i do.
Stage illusions, how many people have heard a non-magician say "He/she is using mirrors" when 99.9% of the time, there isn't a mirror anywhere near that illusion.
I do not bend over backwards in order to remove all the doubts that could have at any time during the performance otherwise i would never finish an effect, but i will casually dispel many methods without saying a word.
In some cases, my client has bought my props for me. On at least 5 occasions before a TV performance i have been challenged with an ungimmicked pack of cards to use for the appearance and i could do so and do the mind breaking effect i had already chosen to perform.
I don't think it is always because they want to catch me out, but they use it as a little novelty "These aren't trick cards, we gave them to him !"
Only once i have said 'no' and that was because the cards they gave me were so cheap and tacky they would not even fan slightly. Fortunately i had a brand new sealed deck i told them to open and examine before i went on.
Sure, i could have come up with some excuse as to why they could not touch my cards, shuffle them or even look at them.
One could suggest that you are giving something away if people are suspicious about your props, well that is certainly the case sometimes, but OTHER times, i have been asked before i even did a trick.
It could be a case of audience control, they shouldn't even ask if you are presenting properly, that also is the case sometimes, but OTHER times, people are just curious and often insistant.
I used to use gimmicks all the time and i don't care if other people do. Using a gimmick does not make you any more or less a professional when it comes to performance. Whatever helps you make the presentation more memorable then by all means use it ! The invisible deck, what an absolute killer trick that is if done properly !
Personally i find that i present better when i am not using them and that's why i don't. It is part of my character and performance style.
So before we start telling other people what works for them, maybe we should look at what works for us and why.