Manu has said that by diving in water after reciting thrice the sin-destroying Mantras, one rcaps the fruits of the final bath in a Horsesacrifice.
अपि चाप्सु निमज्जेत जपंस्त्रिरघमर्षणम्। यथाश्वमेधावभृथस्तथा तन्मनुरब्रवीत्॥