John,

Yep! You're on the right track. Use an odd number of steps in your blend, convert to shapes, ungroup, then create two groups from the ungrouped shapes, one of odd numbered blend shapes and one from the even numbered blend shapes. Convert your text to shapes, then mould each letter to the shape of the top and bottom curved lines/shapes. Then either subtract or intersect the text with the 'even number' line/shape group. Color to suit and add a background to make the 'String Text' stand out.

IHTH,
Harry