SEA SALT VS SENNA TEA-PLEASE HELP!

I intend to do the MC, however, I am confused about the following:

The Master-Cleanse states one can drink Senna tea instead, if you can't do the salt water. However, the salt water flush is recommended for the morning, and the Senna tea for the evening. Would there be a problem if the Senna tea is taken in the moring to flush out the colon, instead of the evening?
Thank you
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