While the best method to avoid cross contamination is to keep all cooking areas between gluten and non-gluten free products 100% separate; it is possible to clean your bench tops, pots, pans and utensils adequately enough to avoid contamination. With the exception of wooden items which are porous and therefore have the ability to absorb the gluten proteins and will not be able to be cleaned thoroughly enough.
Unfortunately there are no current studies that have proven whether heating items will break down the gluten protein there are many forums and people who claim that cooking at 600 Degrees Faherenheit or above for half an hour will break down the protein. However that is far beyond the abilities of conventional cooking tools.
Therefore to be sure that you have removed the proteins from your utensils, pots, pans; you will need to wash them thoroughly with boiling hot and soapy water and a new sponge -freshly opened, once this sponge has been used on a surface that held gluten you will NOT be able to use it to clean for gluten free purposes again.
In our household we use specifically colour coated sponges, just the cheap ones for when Brody decides which is not often to help himself to a gluten containing snack and needs to wipe down his plate or bench top. It then goes into his drawer and he can use it for cleaning up the gluten only area or set of tools but never again for any shared or gluten free purposes.
When partaking in normal washing up of dishes was all the gluten free items first so as to avoid transference through the water or change and wash down the sink in between the gluten and the gluten free tools.
Sadly any appliances will not be able to be shared items as they are unable to be cleaned thoroughly enough to ensure that all traces of the proteins are removed. If you desperately need to share a toaster, you can purchase toaster safe baggies from the Coeliac Society and on a flat sandwich press you can always wrap your item in foil so that it never touches the shared surface.
To clean your BBQ or oven you will need to use a commercial grade cleaner and scrub thoroughly. To ensure that you are keeping yourself or your Coeliac safe, cook their food first on/in the clean grill/oven and then cook the gluten containing items. You may also cook all their items on a piece or wrapped in foil.
There are many factors to take into consideration when attempting to clean to avoid cross contamination but it will keep yourself or the coeliac you are cooking for healthy, happy and coming back for more if you can safely provide for them.