Review the original item:
No foot powder, no shoe insert, no expensive soap can kill the odor of Bartholomew's
feet,
when this young man takes off his shoes, even the goldfish gag.
You chose the correct way to fix the error:
No foot powder, no shoe insert, no expensive soap can kill the odor of Bartholomew's
feet. When this young man takes off his shoes,
even the goldfish gag.
No foot powder, no shoe insert, no expensive soap can kill the odor of Bartholomew's feet is a complete sentence. When this young man takes off his shoes, even the goldfish gag is the second complete sentence.
You are always correct when you use a period between the two complete sentences that create the comma splice.