Copenhagen suborbitals have successfully tested their BPM-2 liquid rocket engine. BPM-2 is a throat less engine designed to evaluate different fuel mixtures and additives in order to find the most optimum fuel mixture ratio for the BPM-5 and the future BPM-100.
Water is a common additive in the ethanol fuel to help lower the combustion temperature of the rocket engine (used on the V2), silicon oil can also be added which adds a barrier layer on the inner chamber and throat walls which helps to reduce the heat transfer rate.
The full test video is here with links below to the specific firings.
More info on the additive ‘silicone’ or TEOS as CS use.