Hi Mender, I have shampooed this system about 4 times since February --- I have an old system which I wear with a baseball cap when working in the garden and likely to be sweating a lot --that gets a good rinse -out after use, but I keep the Toplace unit for normal wear. I don`t use lots of products on it, like gels, so I don`t get product build -up leading to a `` lifeless`` look, requiring shampoo/conditioning. I do mist the hair with water which freshens it up nicely. I know everyone has their own preferences --some like to use loads of styling products to give a `funky`look --at my age [ 50 ] I just go for a [ boring!! :-) ] normal head of hair -- I`m sure I`d look strange going around with spikes ! In my case, my own hair is quite fine and thin now, so I had to re -thin the system last week to match -- a younger person would get away with more volume in their system. I am expecting a new system within the next 2 weeks or so --will post pics when it`s styled -in. I may go full -cap on the system after that, but will decide nearer to ordering -time. I suppose the best way to decide when to shampoo is just see how the system looks --try misting with water , `ruffle`the hair up with your finger tips and leave to dry naturally overnight, or when you have attached it, mist it , and ruffle it up,allowing to dry, and you`d be surprised at how that can help avoid washing the guts out of it --also once a week , slightly back -comb/brush the hair, and spray in-- lightly -- some leave -in conditioner, occasionally I spray in a silicone -based gloss spray [purely for shine ] --but again use fairly sparingly --too much products just logs the hair down and it looks lifeless. I have rinsed the system carefully [without shampoo ] on occasions when I had been sweating --- the acid in sweat can and does cause damage to ANY base material --even polyurethane will eventually get little tears and holes from sweat. On the occasions I have shampooed it, I also gently worked conditioner through the hair, allowed it to `sit`for a few minutes and then rinsed out.Personally, I have the little poly strip purely for ease of attachment/detachment as you can just use a few little strips of tape [very easy to work with ] or for a full -bond, you tape the unit while it`s off your head, applying tape to the poly part, position it, and use glue for the lace front. I have often just taped the `straight`parts of the poly, but where it curves at the back, I use glue---it`s really easy as you peel off the backing tape, and apply the unit to the scalp, then using 2 mirrors [easier to sit at a table/dressing table with a large mirror and a hand -held mirror] just fold up the back part where the curve is, and apply a layer of glue onto the poly with brush --then just allow it to fold back down onto the skin --you get no glue stuck to your own hair that way. It can be tricky if you apply glue to the scalp first and then try to position the system onto that-- the trade -off for using a part -poly piece is that the poly is that bit thicker/heavier than lace so it would be more detectable to the touch, but for me, if I do a full perimeter bond, there is hardly any difference and it`s just easier to apply and totally easy to clean as the tape peels off cleanly without the need for de -bonder liquids /kitchen towel. It`s a matter of choice /preference Mender, and I`m only spitting it out for information so you can make an informed choice on what way you want to `go` and I`m sure after a while of wearing ,you`d have your own ways and likes /dislikes --- I know it all sounds a bit `involved`for those considering making the leap into DIY but after a while you`ll be wondering why you didn`t do it sooner! Regards, Paul.