people usualy give reference for things like above mentioned as being " 5000 yers old"...and "2500 years old" and.."10,000 years old"...we have a general misconception about many things that if are old then good and reliable....like we see in different ads of DABAR ayurvedi products ...some old saadhu are shown making some kind of powder and paste using old time tools of stone or marble...and we get impressed by that thinking this has been used for cures of this and that for thousand years so it is genuinely effective. Not everything which is old and taught or practised by some rishi muni has to be very authentic and applicable to todays world.