I'm working with an evil pony for his owner, who is VERY soft with him, but she understands the need for firmness... she just can't do it herself due to a severe lack of physical strength such that she can barely even hold a whip in her hand, forget about using it! She watches what Mum and I do with said pony, takes it all in, but can't do it herself.
Unfortunately, butterflies and rainbows just don't work. If that's what these owners want, then don't bother. Can't fix stupid.