I don't need any particular technique for your Bitcoin holders just store it in a hardware wallet and it's safe and no one will reach it individually, no need to worry about tracking the flow of funds because we haven't committed a crime so what is there to be afraid of?
You are absolutely right in stating that investing in Bitcoin is not inherently illegal. However, it is unfortunate that in some parts of the world, investing/trading in crypto currencies is considered illegal, which is seen as unfair fair and against the interest of general public. In this situation, safeguarding privacy of investment is crucial to avoid any unforeseen circumstances.
It is essential for all of us to persistently raise our voices on all available platforms to advocate the regulation of Bitcoin. This concentrated effort can build pressure on legislators to address this long standing issue that affects many.