Generally In hindu funeral people cremate(for non sanyasis)the dead and on the third day people collect ashes/bones, and throw them into river also known as Asthi sanchaya.
The asthi sanchaya rite dictated in Ashvalayana Grhiya Sutra (page no 55) is different then what most of people do.
It says that asthisanchaya should be performed after 10th tithi from death
The gathering (of the bones is performed) after the tenth (Tithi from the death), (on a Tithi) with an odd number, of the dark fortnight, under a single Nakṣatra.
while it is generally done on third tithi from death, and the final destination of asthi is also different from what sutra says, it says asthi should be buried inside a pit rather then giving it to flowing water. (See Adhayaya 4 Kanda 5 verse 7 and 8).
Having well gathered them and purified them with a winnowing basket, 269 they should put (the urn) into a pit, at a place where the waters from the different sides do not flow together, except rain water, with (the verse), 'Go to thy mother Earth there' (Rig-veda 10:18, 10).
With the following (verse) he should throw earth (into the pit)
