The "better" Helicoil versions are called Time-sert or other brand names with "sert" stuck on the end. They are not cheap.
The safest way to fix is to remove the head - people try and mess about with compressed air to try and blow swarf out of the cylinder but I think that's potentially asking for trouble. If you have an engine with an aluminium alloy head it is probably a good idea to remove it anyway and check for corrosion (especially if the engine has been sitting for a while / poor maintenance). More modern engines such as the M102/3/4 and the OM603/6 suffer from head gasket corrosion related trouble.
For my M102 I used Hylomar spray on gasket dressing which is meant to help prevent corrosion as well as help with the seal.
If you decide to remove the head follow the reverse torque order procedure as specified in the FSM - this is particularly important for an aluminium alloy head.
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