sed -e :a -e '$!N;s/\n [0-9A-F][0-9A-F] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] [0-9A-F ][0-9A-F ] |\([^|]\+\)|/\1/;ta' -e 'P;D' logfile
on Linux will convert the hex dumps in logfile
into strings (with control characters and spaces kept as periods), leaving other lines intact. So you can just redirect this to a file or pipe it into your favourite pager, e.g. less. You might need to take account of the fact that control characters and spaces are shown as periods when searching for multiple word strings.
With non-GNU sed it might be necessary to change \+
into *
.