With RGH3 you technically don’t absolutely need a flasher since you can technically flash from within the BadUpdate jailbreak, but a flasher is nice if you need to recover the nand if something goes wrong.

But you may want to consider just going the BadAvatar route. My soldering skills are above average after university but if you’re not used to SMD stuff you will struggle. BadAvatar takes less than a minute and will boot you into Aurora right after it finishes.

Its also worth noting that some later slims can’t be hardmodded at all so just look out for that. I would recommend the consolemods wiki and if you look on YouTube you’re bound to find some resources