[2][3] During her study of anesthesiology, two incidents made her aware of the dangers of alternative medicine: the first case was a 48-year-old woman with breast cancer, who had put her faith in a treatment by a naturopath, but whose condition had become hopeless by the time she was hospitalised.

She opines that alternative therapists merely give their clients a "medically empty treatment ritual", make them dependent, waste their time and money and miss the opportunity to properly inform them.

Following the example of the Merseyside Skeptics Society in 2010 (that in turn was inspired by SKEPP's action in 2004), De Jong and Maarten Koller together with 30 members of the VtdK and Stichting Skepsis organised the Dutch version of the international 10:23 Campaign.

In a response the article, De Jong claimed that there is no functional solution at all in those dilutions, and it would be honest consumer information if manufacturers would put content indications on all homeopathic products, in the same manner that is compulsory for actual medicines.

[11] In a November 2011 letter, De Jong accused rector Martin Kropff of Wageningen University of 'providing a platform for pseudoscience' by approving a lecture series, which allowed several alternative therapists to speak on biophysical medicine.

[16] While drug rehabilitation is developing into a speciality that was recognised by the Royal Dutch Medical Association (KNMG) in December 2012, De Jong warned that there is no alternative treatment that has been shown to effectively help addicts, while in some cases patients are deliberately taken advantage of.

[21] On 3 October, the Meester Kackadorisprijs, the VtdK's annual ironic award, was given to chair Pauline Meurs of ZonMw for her report that recommended to conduct more research into alternative medicine, which De Jong called a waste of valuable time, money and manpower, seeing that the past 40 years of testing have never resulted in anything beyond the placebo effect.