When Lockwood and Co get de-aged, Barnes gives them to Kipps and his crew to care for and Kipps pretty quickly realises you can get little Lockwood to do pretty much anything if you offer him something you are pretending to be valuable. Like he needs Lockwood to brush his teeth so he starts talking about how cool this pen he found in his pocket is and then tells Lockwood to go and brush his teeth and Lockwood is like 'I will brush my teeth if you give me the super cool pen' and Kipps agrees. Only Kipps realises he never sees the stuff he gives Lockwood again so he starts following Lockwood around because he is running out of pocket junk to give the little boy only to find out that every super cool thing Lockwood earns is given straight to little Lucy.
Also, this plays out: