into cooling circuit 14 to reduce toxicity and or hostile action of any cleaning agent remaining in cooling circuit 14 for example a neutralization agent supply 122 can be connected to conduit 110 and or pressurization apparatus 130 so that neutralization agent can be fed into cooling circuit 14 to avoid accidental removal of coating 24 from areas in which it is desired a masking agent 29 fig2 such as a coating can be applied before cleaning agent is supplied to cooling circuit 14 so that cleaning agent escaping cooling circuit 14 such as through cooling hole s 12 does not react with coating 24 that is covered by masking agent 29 with reference to fig3 embodiments of the invention disclosed herein can employ a different approach to avoiding accidental removal of coating 24 that can avoid the use of masking agents entirely more specifically neutralization agent supply 122 can be placed in a tank 124 or the like into which turbomachine part 10 can be immersed with turbomachine part 10 so immersed cleaning agent can be supplied to cooling circuit 14 and any cleaning agent that escapes through cleaning holes 12 is neutralized as it escapes into neutralization agent supply 122 in embodiments rather than immersing turbomachine part 10 neutralization agent can be sprayed or otherwise applied to turbomachine part 10 as cleaning agent is supplied to cooling circuit 14 for example as seen in fig1 one or more spray heads 126 could be connected to neutralization agent supply.