Sorry to say, but yes. A friend of mine wore a small microphone that transmitted a very high and not very loud frequency, so that a TD two tables away could not hear it, but the other player could. The buzzing antagonated the opposing player and threw off his thought process, and whenever his opponent asked my friend if he heard anything, he said no, and maybe his opponent should get some more sleep. This is truly the very CHEAPEST trick in the book.
hahahaha
PLATOLAG - I've never tried any of the products they mention nor heard anything about them. I notice they do mention the herb Ginko, which I have read somewhere that it is supposed to help cerebral blood flow. I cannot atest to that, but can mention I have used Ginko in the past, and found it seems to help my memory, especially short term memory (as is vital to otb Chess analysis) where I normally have a problem otherwise (from illness). They also mention fish oil, tho I do not know in what capacity. But one may be as a source of Choline, which is a precursor for the body to produce the neurotransmitter, acetylcholine, that is used in both muscle & the brain. (For instance, the illness Myasthenia Gravis involves a deficit of usable acetylcholine and results in extreme weakness.) In addition to fish oil, there are also choline capsules at nutrition stores. But the last I heard, there was not hard evidence available showing that it was actually being converted to acetylcholine, when taken orally. On the other hand, I have tried choline and thought it helpful. Or else "lecithin", that is supposed to produce choline.
It is unfortunate that they do not list all the ingredients. Some products on the market will include Ginseng or ephedrine to act as stimulants. (The latter being a very powerful one as it is a precursor of epinephrine. When produced by the body, epinephrine is also called "adrenalin" .) That may not necessarily be a good thing, if someone feels perky from stimulants they may not be able to tell if the other ingredients are really helpful, and also there is a price to be paid for use of stimulants as they can be hard on the body, and lose effect also over a period of use. Or there may be chromium picolinate included which has lesser effects of stimulation and is also a diuretic.
I am not recommending anything. But just trying to state what my experience was. Many things do not seem to work the same for others, however.