As far as I can tell, there are no good answers in the answer linked above:

• The accepted answer only checks raw files in the same directory.
• Those that search the raw file elsewhere will possibly erase the wrong files, because they make the wrong assumption that image file names are unique(*).

To be really safe:

• If the file time stamps have been preserved you can check the file time stamps, with at least a 2-seconds fuzz margin since CR2 and JPEG have a different stamp and the FAT filesystem on the camera cards only keeps time to 2 seconds of accuracy.
• Otherwise you would have to check the EXIF data of like-named JPEG and RAW file and see if they match.

I do have a similar script based on file time stamps (it reconciles a CR2 with its JPEG counterpart elsewhere in the directory tree)

Quickly whipped up script using file timestamps, seems to work on my files, use at your own risk:

#! /bin/bash

# Change these to your liking or set them from parameters
jpegDir=/path/to/jpegDir    # Top directory for JPEG
rawDir=/path/to/rawDir      # Top directpry for Raw
timeFuzzSeconds=10          # Max time difference between JPE and raw    

shopt -s extglob
shopt -s globstar

# For all JPEG, find if a like-named raw file exist with a similar timestamp, and delete it
for jpg in $jpegDir/**/*.@(jpg|JPG|jpeg|JPEG)
do
    jpgBase=${jpg##*/}
    rawRootName=${jpgBase%.*}
    jpgTime=$(stat -c "%Y" "$jpg")
    rawMinTime=$((jpgTime-timeFuzzSeconds))
    rawMaxTime=$((jpgTime+timeFuzzSeconds))
#    printf "Searching %s between %s and %sn" $rawRootName "$(date -d @$rawMinTime '+%F %T')" "$(date -d @$rawMaxTime '+%F %T')" 

    # Replace "-print" at the end by "-delete" when you are confident that it works as expected
    # "-print" will only show you the files without touching them
    find $rawDir  -newermt @$rawMinTime  ! -newermt @$rawMaxTime -regextype egrep -regex '.*/'$rawRootName'.(CR2|NEF|DNG)' -print
done

(*) The counter used for names in cameras rolls over at 9999, so the assumption doesn't hold for a large collection from a single camera, and even less so if there are several cameras.

Some clarification needed

First of all 3 questions in order to allow for a more complete answer:

1. What Operating system (Windows, OS X, Linux) will you run these scripts on?
2. are the JPG files using the same name as the RAW files? Just a different suffix? Or if not, is there another way to link a RAW file to a JPEG file?
3. Is there a fixed folder structure/hierarchy?

Example Bash Script

You can create a simple script that will iterate over all RAW files and check if there is a JPEG variant and delete if so. Depending on the above answers I can provide you a script for that.

If those files are within the same folder and easily matched it's a very quick and easy script that will execute in minutes. If those files are organized in folders it will require some more extensive find commands that will take a bit more time for the script to execute.

For bash for example this will work if

• all files are in one directory, put script in that directory
• .CR2 and .JPEG extension are the only differences between the filesets

for f in *.CR2 ; do [ -e "${f%.CR2}.JPEG" ] && rm "$f"; done

Use with caution cause this will remove files using that rm command at the end!?